This disclosure relates generally to optical data systems, and more particularly, to an authenticable optical disc and systems for authenticating optical discs and methods thereof.
Billions of dollars are lost every year due to copyright infringement. A common loss of revenue is through the unauthorized replication & distribution of optical media, e.g., compact discs (CDs) and digital video discs (DVDs). There have been many attempts to prevent copying of discs and limiting access to data on unauthorized copies of discs. Such methods include encoding patterns, applying coatings, or “burning” regions on the disc that result in errors in the datastream. Software encoded in the media “looks” for these errors and, if they are present, the rest of the software is allowed to execute. Unfortunately, these methods are easily defeated. Software programs such as “CDclone” or “Blindwrite/Blindcopy” actually look for these copy-protection regions in the datastream and re-create them so that the copy is similar to the original.
In Cyr et al., U.S. Pat. No. 6,099,930, tagging materials are placed in materials such as digital compact discs as a means to determine the authenticity of the compact discs. A near-infrared fluorophore is incorporated into the compact disc via coating, admixing, blending, or copolymerization. Fluorescence is detectable when the fluorophore is exposed to electromagnetic radiation having a wavelength ranging from 670 nanometers to 1100 nanometers. An illumination source provides excitation light that impinges upon or penetrates the compact disc. Once excited, the near infrared fluorophore emits light at a longer wavelength than the respective wavelength of the excitation light. At least some of the fluorescent light and a portion of the excitation light are reflected by the compact disc and is directed towards a camera. The camera then produces an electric signal suitable to generate an image directly on a viewing means. The compact disc is then authenticated by a user viewing the image or by an image recognition device/software process.